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Cost-Effective Three-Phase Current Amplifier Interface for Real-time Simulator with Relays in-the-Loop...

by Maximiliano F Ferrari Maglia, Emilio C Piesciorovsky, Joshua C Hambrick, Travis M Smith
Publication Type
Conference Paper
Journal Name
IEEE Xplore
Book Title
2019 North American Power Symposium (NAPS)
Publication Date
Page Numbers
1 to 5
Conference Name
51st North American Power Symposium (NAPS)
Conference Location
Wichita, Kansas, United States of America
Conference Sponsor
Conference Date

This paper presents a prototype of a simple and cost-effective design using a high-power monolithic power amplifier that allows the relay in-the-loop connectivity for protection and control applications using a real-time simulator. This low-cost amplifier interface increases the number of protective relays in-the-loop connected with the real-time simulator, expanding the scalability of protection devices that could be tested. The amplifier control design was developed in abc coordinates and utilizes integral and proportional-resonant controllers to provide a good tracking of both the fundamental component as the dc component that might be present during fault conditions. To validate the prototype, the current signals and tripping time of a relay interfaced with the current amplifier were compared against a reference relay connected to the low-voltage interface. Both protective relays were set with a U3 Very Inverse time overcurrent curve. The experimental results exhibited similar behaviors for the breaker currents, validating the amplifier interface prototype.